Expansion pulley



Dec. 27, 1932. i RUNDELL 1,892,252

EXPANS I ON BULLEY Filed Jan. 24 1930 &

Patented Dec. 27, 1932 UNITED STATES PAT OFFICE RU R RUN ELL F .BQCK I LE CE E NEW YORK, ASS GN R- T0 A B C MACHINE & FOUNDRY COMPANY, A osromrlol o n w JERSEY EXI PANSION PULLEY A pplication filed January ,24, 1930. Serial No. 423,168.

This invention relates to expansion pulleys such as are used in continuous rod cigarette machines to drive the rod impelling tape. In such machines it is desirable to vary the i 5 linear speed of the tape with respect to positively driven parts of the machine from time to time, in order to maintainthe relative speed of the cigarette rod constant with re.- spect to the cutoff mechanism and other parts of the machine; this being necessary because the cigarette rod slips somewhat with respect to the tape which slip varies with the condition of the tobacco and other operating conditions thereby changing the length of the cigarettes cut, if not compensated for. This adjustment has been accomplished by wrapping the pulley with tape to increase its diameter and by providing a pulley having radially expansible shoes surrounded by a stretchable rubber element, which have not been fully satisfactory. The latter, while it was an improvement on wrapping the pulley with tape was somewhat unsatisfactory owing to the fact that the flexible rubber rim element stretched flat between shoes so that the pulley was not round and moreover the rubber being somewhat yielding permitted the tape to hesitate when for any reason the tape offered resistance and when accelerating 0 and decelerating. Moreover the rubber surfaces do not provide as good traction as the rough surface of a tape.

The main object of the present invention is to provide an expansion pulley which combines the advantages and obviates the disadvantages of the prior devices for the above purpose. To this end it is is an object of the invention to provide an expansion pulley which remains round when expanded. An-

40 other object is to provide a pulley of this type, which since the rim is ordinarily made of steel or like resilient material, would h ave poor traction, with a tape surface; and in which the tape is so secured that it may be quickly made to conform with changes in circumference of the pulley.

With these and other objects not specifically mentioned in view the invention consists in certain constructions and combina- 0 tions which will be hereinafter fully described and then specifically set forth in the claim er n o app de In the accompanying drawing which forms a part of this specification and in which like characters of reference indicate the same or like characters, Fig. 1 is a side view partly broken away of an expansion pulley constructed in accordance with the invention; Fig. 2 is a sectional View on the line 2 -2 of Fig. 1.

In carrying the invention into effect there is provided, in an expansion pulley, for driving tapes and the like, a radially expansible mechanism, and a resilient split rim surrounding said mechanism. Preferably this rim is of steel. In the best constructions traction providing means surround said rim and preferably this means comprises a lining tape wrapped around said rim and take-up device for holding said tape taut and anchoring it to the pulley,

The Various means referred to may be varied widely in construction within the scope of the claims, for the particular'device selected to illustrate the invention is but one of many possible concrete embodiments of the same. The invention therefore is not to be restricted to the precise details of the struct r s own and de c ib d Referring now to the drawing, the improved pulley includes radially expansible mechanism comprising a hub 12 secured on the drive shaft 10 by akey 11,.to which hub is secured by means of screws 13, a disc shaped body 14; having a number of symmetrically arranged radial grooves in which are slidable shanks l5 carrying at their outer end a circular series of shoes l5a. The shanks are held in the grooves against axial movement by a cover plate 16 attached to a disc 1 by screws 17 The inner ends of the shanks 15 are machined to fit the taper of a conical nut 18 screwed upon the end of the hub 12 and movable axially upon it. Thus turning of the nut causes asimultaneous radial expansiOn of the circular series of shoes 15a.

Surrounding the circular series of shoes 15a is a split steel rim 19 so dimensioned that i latter are in their innermost position. Diametrically opposite the split or slot between the ends of the rim, the rim 19 is fastened to the periphery of one of the shoes by a screw 20. The front face of the pulley, outside of the nut 18, is covered by side plate 21 attached to the cover plate 16 of the shank supporting disc 14 by screws 22. The rear surface of the pulley, exterior to the flange hub 12, is covered by the plate 23 attached to disc 14 by screws 24:, the cover plates 21 and 23 forming the end flanges of the pulley for retaining the rim 19 in place and for guiding the tape 25 carrying the cigarette rod C.

The resilient steel rim 19, while it has the advantage that it may be expanded without losing its roundness has very poor traction. Accordingly, the steel rim 19 is wrapped with a rough textured tape lining 26 which is not secured to the rim but the ends of which are carried through the slot of the split rim and wrapped around an arbor 27 supported in the side plates 21 and 23. The ends of the tape are fastened in an axial slot of this roller by wedge 28. The arbor 27 has a projecting square end 29 by means of which it can be rotated to pay out, or take up and thustightening the lining 26. Engaging the square end of the arbor 29 is mounted one end of a slottedlockpiece 30, heldin position by the screw 31 disposed in its slot and threaded into the side plate 21, which serves to releasably lock the roller 27 after each adjustment of the tape. p

By the arrangement described, the diameter of the tape wheel can be quickly and ac-' curately adjusted to the varyin condition of the tobacco, so that the speed of the tape belt 25, which by means of the idler 32 is made to almost completely surround the tape'wheel, can more conveniently and accurately be adjusted to properly synchronize the travel of the cigarette rod with the operation of the cutoff, feed and other parts of the cigarette machine, thus producing a more uniform product.

What is claimed is:

1. In an expansion pulley for driving tapes and the like, the combination with radially expansible mechanism, of an expansible split rim surrounding said mechanism, and traction providing means surrounding said rim, said means including a lining tape wrapped about said rim and having its ends extending through the slot in the rim, and a rotatable arbor to which said ends are secured and releasable means for locking said arbor against rotation.

2. In an expansion pulley for driving tapes and the like, the combination with radially expansible mechanism, of an expansible split rim surrounding said mechanism, and traction providing means surrounding said rim, said means including a tape surrounding said rim and having its end portion extending through the slot in the rim, and releasable means acting on said end portion to anchor the tape.

'3. The combination with an expansion pulley, of a lining tape wrapped about the rim of said pulley, and releasable means within said pulley for holding said tape taut, said releasable means including a slotted arbor rotatably mounted in said pulley, means for anchoring the ends of said tape in the slot in said arbor, and means for locking said arbor against rotation.

4. The combination with an expansion pulley, of a lining tape wrapped about the rim of said pulley, and releasable means within said pulley for holding said tape taut, said means comprising a tape securing element adjustable on said pulley to loosen or tighten the tape and mechanism for locking the same in adjusted position.-

5. The combination with an expansion pulley having a slotted rim, of a tape for providing traction surrounding said rim and having a surplus portion extending through the slot, and releasable tape tightening means acting on said surplus portion to anchor the tape to said pulley, said device comprising a rotatable arbor on the pulley to which said portion is secured and releasable means for locking the arbor against rotation.

In testimony whereof, I have signed my name to this specification.

RUPERT E; RUNDELL. 

